.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)ht.4	6.2 (Berkeley) 1/28/88
.\"
.TH HT 4 "January 28, 1988"
.UC 2
.SH NAME
ht \- TM-03/TE-16,TU-45,TU-77 MASSBUS magtape interface
.SH SYNOPSIS
.ft B
.nf
/sys/conf/SYSTEM:
	NHT	\fIht_drives\fP	# TE16, TU45, TU77

/etc/dtab:
.ta .5i +\w'#Name 'u +\w'Unit# 'u +\w'177777 'u +\w'Vector 'u +\w'Br 'u +\w'xxxxxxx 'u +\w'xxxxxxx 'u
	#Name	Unit#	Addr	Vector	Br	Handler(s)		# Comments
	ht	?	172440	224	5	htintr		# tu 16 massbus tape
.DT

major device number(s):
	raw: 6
	block: 0
minor device encoding:
	bits 0003 specify HT drive
	bit  0004 specifies no-rewind operation
	bit  0010 specifies 1600BPI recording density instead of 800BPI
.fi
.ft R
.SH DESCRIPTION
The tm-03/transport combination provides a standard tape drive
interface as described in
.IR mtio (4).
All drives provide both 800 and 1600 bpi; the TE-16 runs at 45 ips,
the TU-45 at 75 ips, while the TU-77 runs at 125 ips and autoloads tapes.
.SH FILES
.ta \w'/dev/MAKEDEV.local  'u
/dev/MAKEDEV	script to create special files
.br
/dev/MAKEDEV.local	script to localize special files
.DT
.SH "SEE ALSO"
mt(1),
tar(1),
tp(1),
mtio(4),
tm(4),
ts(4),
dtab(5),
autoconfig(8)
.SH DIAGNOSTICS
\fBtu%d: no write ring\fR.  An attempt was made to write on the tape drive
when no write ring was present; this message is written on the terminal of
the user who tried to access the tape.
.PP
\fBtu%d: not online\fR.  An attempt was made to access the tape while it
was offline; this message is written on the terminal of the user
who tried to access the tape.
.PP
\fBtu%d: can't change density in mid-tape\fR.  An attempt was made to write
on a tape at a different density than is already recorded on the tape.
This message is written on the terminal of the user who tried to switch
the density.
.PP
\fBtu%d: hard error bn%d er=%b ds=%b\fR.   A tape error occurred
at block \fIbn\fR; the ht error register and drive status register are
printed in octal with the bits symbolically decoded.  Any error is
fatal on non-raw tape; when possible the driver will have retried
the operation which failed several times before reporting the error.
.SH BUGS
If any non-data error is encountered on non-raw tape, it refuses to do anything
more until closed.
.PP
The system should remember which controlling terminal has the tape drive
open and write error messages to that terminal rather than on the console.
